An antenna apparatus that can be miniaturized without causing inference caused by antenna currents to be occurred if the high band of a dual band wireless system is close to the band of another wireless system in a wireless communication apparatus incorporating the dual band wireless system and another wireless system is provided. A first switch 5 blocks passage of a signal of a high band (first frequency) and allows passage of a signal of a low band (second frequency). A second switch 6 blocks passage of a signal of the low band (second frequency) and allows passage of a signal of the high band (first frequency). Accordingly, the antenna apparatus operates as a dipole antenna with no antenna current flowing into a feeder line at the first frequency and operates as a monopole antenna wherein a radiation element and a feeder line making up the dipole antenna becomes a radiation element at the second frequency lower than the first frequency.